Apparatus for producing color filter with alignment error detection

ABSTRACT

This invention relates to a highly precise and efficient color filter producing apparatus, which is provided with at least a set of drawing heads for respectively generating ink jets of red, green and blue colors, movement device for moving, with a substrate on which a color filter is to be formed by drawing with said ink jets, in a plane having a predetermined distance from the drawing heads, displacement detection device for detecting relative displacement between the substrate and the drawing heads in directions of six degrees of freedom, device for detecting the reaching position on the substrate of the ink jet discharged from the drawing head, and alignment device for effecting alignment between the substrate and the drawing heads in directions of six degrees of freedom, based on the results of detection of the reaching position and of the relative displacement between the substrate and the drawing head in directions of six degrees of freedom.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a technology for producing a colorfilter for a color liquid crystal display adapted for use in a colortelevision, a personal computer or the like, and more particularly to amethod and an apparatus for producing a color filter by arranging pluralcolored filter elements on an optically translucent substrate, the colorfilter, a liquid crystal display device and an apparatus having suchliquid crystal display device.

2. Related Background Art

For producing the color filter, there are conventionally known thedyeing method, the pigment dispersion method, the electro-depositionmethod, the printing method etc.

The dyeing method prepares the color filter by forming a layer of awater-soluble polymer material, for dyeing, on a glass substrate,forming the above-mentioned material into a desired pattern by aphotolithographic process, then immersing the glass substrate into adyeing bath to obtain a colored pattern, and repeating this processthree times for red, green and blue colors.

The pigment dispersion method prepares the color filter by forming alayer of photosensitive resin, in which pigment is dispersed, on a glasssubstrate, then patterning the resin layer to obtain a mono-coloredpattern and repeating this process three times for red, green and bluecolors.

The electrodeposition method prepares the color filter by forming atransparent electrode pattern on a glass substrate, then immersing theglass substrate in an electrodeposition liquid containing pigment,resin, electrolyte etc. for depositing a single color, and repeatingthis process three times for red, green and blue colors.

The printing method prepares the color filter by printing thermosettingresin, containing dispersed pigment, three times respectively for red,green and blue colors and then thermally setting the resin.

These four methods in common require repetition of a same process bythree times for forming red, green and blue colors, and such largenumber of steps reduces the production yield and increases the cost.

Besides, the electrodeposition method is hardly applicable to the TFTliquid crystal display since the formable pattern is limited in shape.Also the printing method is limited in resolution and cannot thereforebe applied to finer patterns.

In order to resolve these drawbacks, there is proposed a method offorming the filter pattern by ink jet emission onto the glass substrate,as disclosed in the Japanese Patent Laid-Open Application Nos. 59-75205,63-235901, 1-217320 etc.

SUMMARY OF THE INVENTION

However, such technology utilizing ink jet has not yet been developedfor the functions for production. More specifically, highly precisepattern formation is not possible because there has not been developed asystem, for example, of measuring the reaching position of ink inadvance, then aligning the glass substrate in directions of six degreesof freedom with respect to the drawing head (or aligning the drawinghead with respect to the glass) in mounting the glass substrate on themanufacturing apparatus, and maintaining a constant gap between thedrawing head and the glass substrate in pattern drawing. Also noconsideration has been given on the productivity.

An object of the present invention is to resolve such drawbacks and toprovide a method and an apparatus for producing the color filter, whichare inexpensive and highly reliable, and are capable of satisfying thecharacteristics of the conventional methods, such as resolution,exploiting the feature of the ink jet method.

More specifically it is to enable highly precise drawing of each colorpattern of red, green and blue colors on the substrate with measures foravoiding dusts and improving the productivity, and also to enableflexible adaptation for example to a change in the size of thesubstrate.

Another object of the present invention is to provide a color filterproduced by the above-mentioned method or apparatus, a liquid crystaldisplay device and an apparatus equipped with such liquid crystaldisplay device.

The above-mentioned objects can be attained, according to the presentinvention, by an apparatus for producing a color filter comprising atleast a set of drawing heads for respectively generating ink jets ofred, green and blue colors, movement means for moving with a substrateon which the color filter is to be formed by drawing with ink jets,displacement detection means for detecting relative displacement betweenthe substrate and the drawing heads, means for detecting the reachingposition, on the substrate, of the ink jet discharged from the drawinghead, and alignment means for effecting alignment between the substrateand the drawing head, based on the result of detection of the reachingposition and that of the relative displacement.

It is also featured by facts that the drawing heads are fixed above thesubstrate and that the alignment means and the movement means are bothadapted to move the substrate in the alignment and in the drawingoperation.

It is further featured by a fact that, for each drawing head, itsreaching position is detected in advance for a surface in apredetermined positional relationship thereto.

It is further featured by a fact that the length of the drawing heads ofred, green and blue colors is equal to the width of the substrate in thedrawing direction.

It is further featured by a fact that plural sets of drawing heads arearranged in parallel with an entire length equal to the width of thesubstrate in the drawing direction.

It is further featured by a facts that the drawing heads are adapted toindependently generate ink jets of red, green and blue colors, that themovement means is adapted to move within a plane of a predetermineddistance from the drawing heads and that the relative displacement andthe alignment are achieved in the directions of six degrees of freedom.

Also according to the present invention, there is provided a method forproducing a color filter in the above-mentioned apparatus by drawing onthe substrate with the drawing heads under the movement of thesubstrate, comprising steps of detecting the relative displacementbetween the substrate and the drawing heads by the displacementdetection means, detecting the reaching position, on the substrate, ofthe ink jet discharged from the drawing head, and effecting alignmentbetween the substrate and the drawing head based on the result ofdetection of the reaching position and that of the relativedisplacement.

According to the present invention, in loading a substrate such as aglass substrate bearing a black matrix thereon on the movement means,there are detected the displacements in the X-direction (perpendicularto the head), the Y-direction (in the head scanning direction) and theθ-direction (rotation on the X-Y plane) by means of the displacementdetection means for detecting the displacement of the alignment betweenthe drawing head and the substrate, and the relative position betweenthe head and the substrate is adjusted. The displacement is detected bydetecting marks provided in two positions on the substrate with amicroscope under the activation of the movement means, or bysimultaneously detecting the marks on the substrate with twomicroscopes. The relative displacement, measured by the alignmentmicroscope, is corrected by referring to the coordinate, measured inadvance, between the reaching position of the ink discharged from thehead and the alignment microscope (obtained for example by detecting thecoordinates of the reaching position and the alignment position on thestage coordinate system). The drawing operation is conducted inreciprocating motions, with a constant gap control between the head andthe substrate in the Z and tilt directions, under the measurement of theabove-mentioned gap with a focusing sensor (or after only onemeasurement depending upon the accuracy).

In this manner, highly precise high-speed drawing can be achieved as thereaching position of ink is measured in advance. Also the relativeposition between the head and the substrate in the directions of sixdegrees of freedom is always maintained constant, thereby achieving ahigh precision in the drawing. Also the measurement and correction areperformed in real time basis in the Z and tilt directions, an eventualdirectionality in the ink reaching position (in the scanning direction)can be adjusted by the ink discharge timing, thereby achieving thehighly precise drawing operation. Also, even in case the direction ofdischarge is displaced perpendicularly to the scanning direction, thereaching position is always reproduced and the highly precise drawingoperation can be achieved as the gap is always adjusted constant.Besides, the drawing operation in the reciprocating motions improves theproductivity and facilitates adaptation to a larger substrate. Also thepresence of the drawing heads of red, green and blue colors enablessimultaneous drawing of three colors, thus reducing the process incomparison with the conventional process.

By precisely fixing the red, green and blue drawing heads so as todischarge the inks downwards and effecting the alignment of thesubstrate in six degrees of freedom all at the substrate stage side,there are no moving parts above the substrate, so that the dust droppingonto the substrate can be suppressed. Furthermore, in comparison withthe movement of the heads or the microscope, that of the substrateinvolves a smaller mass, whereby the relative movement can be achievedwith a higher speed and an improvement in the productivity can beachieved.

Furthermore, as the apparatus is provided thereon with means formeasuring the reaching position of the drawing head, it is renderedpossible to measure the head characteristics and the reaching positionwithin the apparatus, thereby achieving highly precise drawing.

Furthermore, the use of the drawing head of which reaching position ismeasured in advance enables highly precise drawing operation andsimplifies the configuration of the apparatus.

Also the three heads of red, green and blue colors having a length equalto the width of the substrate in the drawing direction reduces thenumber of drawing operations and thus improves the productivity. Besidesthe configuration of the apparatus can be simplified as the substrateneed not be moved in the Y-direction (perpendicular to the head scanningdirection).

Furthermore, the arrangement of plural sets of three heads in such amanner that their length is equal to the width of the substrate in thedrawing direction facilitates adaptation to a change of the substratesize.

Also according to the present invention there is provided a method forproducing a color filter by discharging a coloring material from an inkjet head under relative scanning motion with respect to an opticallytranslucent substrate, thereby forming, on the substrate, a plurality ofcolored filter elements with the coloring material, comprising a firstdischarge step of discharging the coloring material with a predeterminedpattern under a scanning motion of the ink jet head relative to apredetermined coloring member, a detection step of detecting thereaching position of the coloring material in the first discharge stepon the above-mentioned member, a timing adjustment step of adjusting thedischarge timing of the ink jet head, based on the result of detectionof the reaching position of the coloring material, detected in thedetection step, and a second discharge step of discharging the coloringmaterial with the timing set in the timing adjustment step under ascanning motion of the ink jet head relative to the substrate therebyforming colored filter elements on the substrate.

It is further featured by a fact that the ink jet head mentioned aboveis adapted to effect ink discharge, utilizing thermal energy, and isprovided with a thermal energy conversion member for generating thermalenergy to be given to the ink.

Also according to the present invention there is provided a method forproducing a color filter by discharging a coloring material from an inkjet head provided with plural discharge nozzles under a scanning motionrelative to a translucent substrate, thereby forming, on the substrate,a plurality of colored filter elements with the coloring material,comprising a first discharge step of discharging the coloring materialwith a predetermined pattern under a scanning motion of the ink jet headrelative to a predetermined member, a detection step of detecting thereaching position of the coloring material in the first discharge stepon the above-mentioned member, a posture adjustment step of adjustingthe posture of the ink jet head based on the result of detection of thereaching position of the coloring material on the above-mentionedcoloring member, detected in the detection step, and a second dischargestep of discharging the coloring material with the posture set in theposture adjustment step under a scanning motion of the ink jet headrelative to the substrate thereby forming colored filter elements on thesubstrate.

It is further featured by a fact that the ink jet head mentioned aboveis adapted to effect ink discharge, utilizing thermal energy, and isprovided with a thermal energy conversion member for generating thermalenergy to be given to the ink.

Also according to the present invention, there is provided an apparatusfor producing a color filter by forming a plurality of colored filterelements on an optically translucent substrate, comprising an ink jethead for discharging a coloring material onto the substrate under amovement relative thereto, thereby forming the colored filter elements,detection means for detecting the reaching position of the coloringmaterial discharged by the ink jet head, and adjustment means foradjusting the discharge timing of the ink jet head, based on theinformation on the reaching position of the coloring material detectedby the detection means.

It is further featured by a fact that the ink jet head mentioned aboveis adapted to effect ink discharge, utilizing thermal energy, and isprovided with a thermal energy conversion member for generating thermalenergy to be given to the ink.

Also according to the present invention, there is provided an apparatusfor producing a color filter by forming a plurality of colored filterelements on an optically translucent substrate, comprising an ink jethead provided with plural discharge nozzles for discharging a coloringmaterial onto the substrate under a movement relative thereto, therebyforming the colored filter elements, detection means for detecting thereaching position of the coloring material discharged by the ink jethead, and adjustment means for adjusting the posture of the ink jethead, based on the information on the reaching position of the coloringmaterial detected by the detection means.

It is further featured by a fact that the ink jet head mentioned aboveis adapted to effect ink discharge, utilizing thermal energy, and isprovided with a thermal energy conversion member for generating thermalenergy to be given to the ink.

Also according to the present invention, there is provided an apparatusfor producing a color filter by forming a plurality of colored filterelements on a translucent substrate, comprising an ink jet head providedwith plural discharge nozzles for discharging a coloring material ontothe substrate under a movement relative thereto, thereby forming thecolored filter elements, and an adjustment mechanism forthree-dimensional adjustment of the posture of the ink jet head.

It is also featured in that it further comprises detection means fordetecting the reaching position of the coloring material discharged bythe ink jet head.

It is further featured by a fact that the ink jet head mentioned aboveis adapted to effect ink discharge, utilizing thermal energy, and isprovided with a thermal energy conversion member for generating thermalenergy to be given to the ink.

Also according to the present invention there is provided a color filterformed by discharging a coloring material from an ink jet head onto anoptically translucent substrate under a scanning motion of the ink jethead relative to the substrate thereby forming a plurality of coloredfilter elements with the coloring material on the substrate, the colorfilter being produced by a method comprising a first discharge step ofdischarging the coloring material with a predetermined pattern under ascanning motion of the ink jet head relative to a predetermined coloringmember, a detection step of detecting the reaching position of thecoloring material on the above-mentioned member in the first dischargestep, a timing adjustment step of adjusting the discharge timing of theink jet head based on the result of detection of the reaching positionof the coloring material, detected in the detection step, and a seconddischarge step of discharging the coloring material with the timing setin the timing adjustment step under a scanning motion of the ink jethead relative to the substrate, thereby forming the colored filterelements on the substrate.

Also according to the present invention there is provided a color filterformed by discharging a coloring material from an ink jet head providedwith plural discharge nozzles onto an optically translucent substrateunder a scanning motion of the ink jet head relative to the substratethereby forming a plurality of colored filter elements with the coloringmaterial on the substrate, the color filter being produced by a methodcomprising a first discharge step of discharging the coloring materialwith a predetermined pattern under a scanning motion of the ink jet headrelative to a predetermined coloring member, a detection step ofdetecting the reaching position of the coloring material on theabove-mentioned member in the first discharge step, a posture adjustmentstep of adjusting the posture of the ink jet head based on the result ofdetection of the reaching position of the coloring material, detected inthe detection step, and a second discharge step of discharging thecoloring material with the posture set in the posture adjustment stepunder a scanning motion of the ink jet head relative to the substrate,thereby forming the colored filter elements on the substrate.

Also according to the present invention there is provided a liquidcrystal display device comprising a color filter formed by discharging acoloring material from an ink jet head onto an optically translucentsubstrate under a scanning motion of the ink jet head relative to thesubstrate thereby forming a plurality of colored filter elements withthe coloring material on the substrate, the color filter being producedby a method including a first discharge step of discharging the coloringmaterial with a predetermined pattern under a scanning motion of the inkjet head relative to a predetermined member, a detection step ofdetecting the reaching position of the coloring material on theabove-mentioned member in the first discharge step, a timing adjustmentstep of adjusting the discharge timing of the ink jet head based on theresult of detection of the reaching position of the coloring material,detected in the detection step, and a second discharge step ofdischarging the coloring material with the timing set in the timingadjustment step under a scanning motion of the ink jet head relative tothe substrate, thereby forming the colored filter elements on thesubstrate; another substrate opposed to the color filter; and liquidcrystal compound sealed between the substrates.

Also according to the present invention there is provided a liquidcrystal display device comprising a color filter formed by discharging acoloring material from an ink jet head provided with plural dischargenozzles onto an optically translucent substrate under a scanning motionof the ink jet head relative to the substrate thereby forming aplurality of colored filter elements with the coloring material on thesubstrate, the color filter being produced by a method including a firstdischarge step of discharging the coloring material with a predeterminedpattern under a scanning motion of the ink jet head relative to apredetermined member, a detection step of detecting the reachingposition of the coloring material on the above-mentioned member in thefirst discharge step, a posture adjustment step of adjusting the postureof the ink jet head based on the result of detection of the reachingposition of the coloring material, detected in the detection step, and asecond discharge step of discharging the coloring material with theposture set in the posture adjustment step under a scanning motion ofthe ink jet head relative to the substrate, thereby forming the coloredfilter elements on the substrate; another substrate opposed to the colorfilter; and liquid crystal compound sealed between the substrates.

Also according to the present invention there is provided an apparatuscomprising a liquid crystal display device including a color filterformed by discharging a coloring material from an ink jet head onto anoptically translucent substrate under a scanning motion of the ink jethead relative to the substrate thereby forming a plurality of coloredfilter elements with the coloring material on the substrate, the colorfilter being produced by a method including a first discharge step ofdischarging the coloring material with a predetermined pattern under ascanning motion of the ink jet head relative to a predetermined member,a detection step of detecting the reaching position of the coloringmaterial on the above-mentioned member in the first discharge step, atiming adjustment step of adjusting the discharge timing of the ink jethead based on the result of detection of the reaching position of thecoloring material, detected in the detection step, and a seconddischarge step of discharging the coloring material with the timing setin the timing adjustment step under a scanning motion of the ink jethead relative to the substrate, thereby forming the colored filterelements on the substrate, another substrate opposed to the colorfilter, and liquid crystal compound sealed between the substrates; andimage signal output means for supplying the liquid crystal displaydevice with an image signal.

Also according to the present invention there is provided an apparatuscomprising a liquid crystal display device including a color filterformed by discharging a coloring material from an ink jet head providedwith plural discharge nozzles onto an optically translucent substrateunder a scanning motion of the ink jet head relative to the substratethereby forming a plurality of colored filter elements with the coloringmaterial on the substrate, the color filter being produced by a methodincluding a first discharge step of discharging the coloring materialwith a predetermined pattern under a scanning motion of the ink jet headrelative to a predetermined coloring member, a detection step ofdetecting the reaching position of the coloring material on theabove-mentioned member in the first discharge step, a posture adjustmentstep of adjusting the posture of the ink jet head based on the result ofdetection of the reaching position of the coloring material, detected inthe detection step, and a second discharge step of discharging thecoloring material with the posture set in the posture adjustment stepunder a scanning motion of the ink jet head relative to the substrate,thereby forming the colored filter elements on the substrate, anothersubstrate opposed to the color filter, and liquid crystal compoundsealed between the substrates; and image signal output means forsupplying the liquid crystal display device with an image signal.

According to the present invention, even if the plural discharge nozzlesof the ink jet head are aberrated in position, the coloring material canbe deposited on an exact position on the substrate by respectivelyadjusting the discharge timing of the coloring material from eachdischarge nozzle, thereby allowing to produce a highly precise colorfilter.

Also, even if the plural discharge nozzles of the ink jet head areaberrated in position, the coloring material can be deposited on anexact position on the substrate by the adjustment of the posture of theink jet head so as to bring each discharge nozzle to an exact position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are partial magnified views of color filters produced bythe method and apparatus of the present invention;

FIG. 2 is a lateral cross-sectional view of the color filter shown inFIGS. 1A and 1B;

FIGS. 3 and 4 are lateral cross-sectional views showing the structure ofa color liquid crystal display panel;

FIGS. 5 to 7 are views showing information processing apparatus in whichthe liquid crystal display panel is used;

FIG. 8 is an external perspective view of an apparatus constituting anembodiment of the present invention;

FIG. 9 is a view showing the details of a stage in the apparatus shownin FIG. 8;

FIG. 10 is a view showing the arrangement of a head and an opticalsystem in the apparatus shown in FIG. 8;

FIG. 11 is a view showing the concept of ink discharge in the apparatusshown in FIG. 8;

FIG. 12 is a flow chart of a drawing procedure in the apparatus shown inFIG. 8;

FIGS. 13 and 14 are views showing the arrangement of the head and theoptical system in other embodiments of the present invention;

FIG. 15 is a block diagram of another embodiment of the color filterproducing apparatus;

FIG. 16 is a schematic view showing the positional relationship of acoloring head, a correcting head, a sensor and a stage;

FIG. 17 is a view showing the configuration of an ink jet head IJH fordischarging ink onto a layer to be dyed;

FIGS. 18A and 18B are views showing the positional relationship among acoloring head, a correcting head and a translucent portion formed on aglass substrate to be colored;

FIGS. 19A and 19B are views showing the coloring method when thecoloring head is inclined with a predetermined angle;

FIGS. 20A and 20B are views showing the coloring method when pluralcoloring head is inclined by a predetermined angle;

FIG. 21 is a view showing an example of the colored pattern formed foradjustment;

FIG. 22 is a block diagram showing an example of the image processingunit for measuring the ink dot reaching position;

FIG. 23 is a flow chart for explaining an adjustment procedure;

FIG. 24 is a view showing scattered displacement of the reached dots;

FIGS. 25A and 25B are views showing the relationship between thecoloring head and the translucent portion when the discharge nozzles ofthe coloring head are scattering displaced;

FIG. 26 is a flow chart of a procedure for detecting the reachingposition and controlling the discharge timing; and

FIGS. 27A and 27B are views showing an example of the colored pattern tobe used in checking the reaching positions from the ink dischargenozzles of the coloring head.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1A and 1B are partial magnified views of color filters produced bythe method and apparatus of the present invention.

The color filter 10, constituting the front face of a color liquidcrystal display employed for example in a portable personal computer, iscomposed, as shown in FIGS. 1A and 1B, of a two-dimensional array forexample of a grid pattern of filter elements 10a colored in red (R),green (G) and blue (B). FIG. 1A shows an arrangement of the filterelements 10a in a simple checkerboard pattern, while FIG. 1B shows anarrangement in a staggered checkerboard pattern. Between the filterelements 10a, there is formed a light shielding frame 10b for forming aclear partition between the filter elements 10a thereby making the imageclearer.

FIG. 2 is a lateral cross-sectional view of the color filter 10 shown inFIGS. 1A and 1B, illustrating a glass substrate 12 constituting the mainbody of the color filter 10, a light shielding frame 10b and filterelements 10a of the different colors formed thereon.

In producing the color filter 10, chromium is deposited by sputtering onthe glass substrate 12, and is photolithographically formed into agrating pattern, thereby obtaining the light shielding frame 10b. Then aliquid-absorbing dyed layer 14, composed for example of cellulose,acrylic resin or gelatin, is formed on the light shielding frame 10b,and liquid droplets (hereinafter called ink) containing a coloringmaterial (dye) are sprayed by an ink jet recording head onto a filterelement forming area of the dyed layer 14, whereby the layer 14 iscolored to constitute the colored filter element 10a. It is alsopossible to use pigment instead of dye, or to use UV curable ink. Thedyed layer 14 may be dispensed with in case of using such pigment or UVcurable ink.

Then a protective layer is formed if required. The protective layer canbe composed, for example, of a resinous material curable with lightand/or heat, or an inorganic film formed by evaporation or sputtering,that is transparent on the color filter and can withstand the subsequentprocesses such as ITO (indium tin oxide) formation and orienting filmformation.

The color liquid crystal display panel is formed in general by placingthe color filter substrate 12 and a counter substrate 54 in a mutuallyopposed relationship and sealing liquid crystal compound 52therebetween. On the inner face of the substrate 54 of the liquidcrystal panel, there are arranged TFT's (thin film transistors: notshown) and transparent pixel electrodes 53 in a matrix array. On theinner face of the other substrate 12, the color filter 10 is so formedthat the R, G, B filter elements are respectively arranged in oppositionto the pixel electrodes, and a transparent counter (common) electrode 50is formed thereon over the entire area. The light shielding frame 10b isusually formed on the color filter substrate 12 (cf. FIG. 3), but it isformed on the opposed TFT substrate in case of the liquid crystal panelof BM (black matrix) on-array type (cf. FIG. 4). On the inner faces ofboth substrates there are formed oriented films 51, which are subjectedto rubbing process for orienting the molecules of the liquid crystal ina specified direction. Polarizing plates 55 are adhered to the outerfaces of the glass substrates, and the liquid crystal compound 52 isfilled into the gap (about 2 to 5 microns) therebetween. The back lightsource is generally composed of a combination of a fluorescent lamp (notshown) and a diffusing plate (not shown), and the display is achieved byutilizing the liquid crystal compound as an optical shutter for varyingthe transmittance for the light of the back light source.

Examples of application of such liquid crystal panel in an informationprocessing apparatus are shown in FIGS. 5 to 7.

FIG. 5 is a schematic block diagram when the above-mentioned liquidcrystal panel is applied to an information processing apparatus havingthe functions as a word processor, a personal computer, a facsimileapparatus and a copying apparatus.

In FIG. 5, a control unit 1801 for controlling the entire apparatus isprovided with a CPU such as a microprocessor and various I/O ports andeffects control by sending and receiving control signals and datasignals to and from various units. A display unit 1802 displays variousmenus and document information, and image data read by an image reader1807. A transparent touch panel 1803, provided on the display unit 1802,is used for entering various items or coordinates on the display unit1802, in response to the depression of the surface with a finger.

An FM (frequency modulation) sound source 1804 stores music information,prepared for example by a music editor, etc., in the form of digitaldata in a memory unit 1810 or an external memory device 1812, andeffects frequency modulation on such music information read from suchmemory. The electrical signal from the FM sound source 1804 is convertedinto audible sound by a speaker unit 1805. A printer unit 1806 is usedas an output terminal for the word processor, personal computer,facsimile apparatus and copying apparatus.

An image reader 1807 for photoelectrically reading original data isprovided in the transport path of an original paper, and is used forreading the originals for facsimile transmission or copying.

A facsimile transmission/reception unit 1808 is used for facsimiletransmission of the original data read by the image reader 1807 or forreceiving and decoding the transmitted facsimile signal, and has aninterfacing function with the external line. A telephone unit 1809 hasvarious telephone functions such as ordinary telephoning and messagerecording.

A memory unit 1810 includes a ROM storing a system program, a managerprogram, the other application programs, character fonts anddictionaries, a RAM for storing application programs and documentinformation loaded from an external memory device 1812, and a video RAM.

A keyboard 1811 is used for entering text information and variouscommands, etc.

An external memory device 1812, utilizing a floppy disk or a hard disk,etc., is used for storing document information, music or voiceinformation, user's application programs etc.

FIG. 6 is a schematic view of the information processing apparatus shownin FIG. 5.

A flat panel display 1901, utilizing the liquid crystal panel explainedabove, displays various menus, graphic information and text information.On this display 1901, there can be entered coordinates or selection ofitems by the depression of the surface of the touch panel 1803 with afinger, etc. A handset 1902 is used when the apparatus is functioned asa telephone. A keyboard 1903, detachably connected with the main bodythrough a cable, is used for various document processing functions andfor entry of various data. It is further provided with function keys1904. There is also provided an insertion slot 1905 for the floppy diskfor the external memory device 1812.

A sheet stacker 1906 supports the original papers to be read by theimage reader 1807, and the read originals are discharged from the rearside of the apparatus. In the facsimile reception, the printing isexecuted by an ink jet printer 1907.

When the above-explained information processing apparatus functions asthe personal computer or the word processor, the information enteredfrom the keyboard 1811 is processed in the control unit 1801 accordingto the predetermined programs, and the image is outputted from theprinter unit 1806.

When it is functioned as the facsimile receiver, the facsimileinformation received from a communication line through the facsimiletransmission/reception unit 1808 is processed by the control unit 1801according to a predetermined program, and the received image isoutputted by the printer unit 1806.

When it is functioned as the copying apparatus, the original is read bythe image reader 1807, and the read original data are released, throughthe control unit 1801, as a copied image from the printer unit 1809.When it functions as the facsimile transmitter, the original data readby the image reader 1807 are processed by the control unit 1801according to a predetermined program and transmitted to thecommunication line through the facsimile transmission/reception unit1808.

The information processing apparatus explained above may be constructedas an integral configuration, incorporating the ink jet printer as shownin FIG. 7, for achieving improved portability. In FIG. 7, componentsequivalent to those in FIG. 6 are represented by the same numbers.

FIGS. 8 to 12 illustrate a color filter producing apparatus embodyingthe present invention, wherein FIG. 8 is an external perspective view ofthe apparatus, FIG. 9 is a detailed view of a stage, FIG. 10 is a viewshowing the arrangement of a drawing head and an optical system, FIG. 11is a view showing the concept of ink discharge, and FIG. 12 is aschematic flow chart of the drawing procedure.

In these drawings, there are shown a base plate 101 for supporting theapparatus, vibration insulating supports 102 for intercepting theexternal vibration, an XY stage 103 provided on the base plate 101 forthe movement of a large stroke, a θ, Z-tilt stage 104 loaded on theXY-stage 103, for θ, Z-tilt alignment, a glass substrate 105 mounted onthe θ, Z-tilt stage 104, R, G, B drawing heads 106 (106a-106c), adetection optical system 107 for detecting the alignment of the baseplate 101 in the X, Y and θ directions, Z-detecting optical systems 108(108a-108c), and an optical system 109 for detecting the reachingposition of the ink discharged from the drawing head 106.

In the above-explained configuration, at the assembly of the apparatus,a dummy substrate (not shown) is loaded and is aligned in the X, Y,θ-directions by the alignment detection system 107, and an evaluatingpattern is drawn with the drawing heads 106a-106c. Then the XY-stage 103is moved and the reaching position is measured by the reaching positiondetecting system 109. In this manner there can be accurately measuredthe coordinate of the alignment detection system 107 and the coordinatesof the reaching positions of the drawing heads 106a-106c. Since thesecoordinate values remain same for other substrates, the above-mentionedmeasurement can only be conducted at the variation of the systemparameter, for example at the assembling of the apparatus or at thereplacement of the drawing heads. It is also possible to measure thereaching positions in another apparatus and to so adjust the apparatusthat the measured values are reproduced on the color filter producingapparatus.

At the production of the color filter, the glass substrate 105 is loadedon the θ, Z-tilt stage 104 as shown in FIG. 12 (step S51), and alignmentin the Z-tilt direction is executed by the θ, Z-tilt stage 104 in such amanner that the surface of the glass substrate 105 is contained in thedetection range (depth of focus) of the alignment detection system 107(step S52). Then displacements of the drawing heads 106a-106c aredetected by the alignment detection system 107, in three directions ofX, Y and θ (step S53). This detection may be conducted by detectingplural marks with plural detection systems, or by detecting plural markswith a single detection system with a stage movement. Based on theresults of such detection, the displacement in the θ component iscorrected by the θ, Z-tilt stage 104, while the displacement in the Xdirection is corrected by an adjustment of the XY-stage 103 in theX-direction. Also the displacement in the Y-direction (print scanningdirection) is corrected either by an adjustment of the XY-stage 103 inthe Y-direction, or by control of the discharge timing from the drawingheads 106a-106c (step S54). Also the reaching position varies, as shownin FIG. 11, if there is a variation in the gap between the glasssubstrate 105 and the drawing heads 106a-106c. Consequently the gap andthe inclination therebetween are determined by the Z-detection systems108a-108c, and the drawing is conducted by the drawing heads 106a-106cunder such control as to maintain a constant gap (step S56). Dependingon the required precision, the measurement and the correction may bemade only at the loading of the glass substrate, and the gap may bemaintained fixed during the drawing operation.

The present embodiment provides the following:

(1) The number of steps can be reduced in comparison with theconventional method, as the drawing operation can be made simultaneouslyfor three colors;

(2) Dust deposition on the glass substrate 105 can be reduced since nomoving parts are present above the XY-stage 103;

(3) The XY-stage 103 can be moved faster to improve the productivity,since the movement of the glass substrate 105 involves a smaller mass incomparison with the movement of the drawing heads 106a-106c and themicroscope of the detection system;

(4) A highly precise drawing operation is made possible as the alignmentbetween the glass substrate 103 and the reaching positions of the inkfrom the drawing heads 106a-106c in the XY plane is measured andcorrected; and

(5) As the gap (in Z-tilt direction) between the glass substrate 105 andthe drawing heads 106a-106c is constantly adjusted, the relativedisplacement is maintained constant in all the directions of six degreesof freedom, whereby the reaching position can always be maintainedconstant even if directionality exists in the ink discharge, therebyalso ensuring a highly precise drawing operation.

FIG. 13 shows the arrangement of the drawing heads 106a-106c in anotherembodiment of the color filter producing apparatus of the presentinvention, wherein components equivalent to those in the foregoingembodiment are represented by same numbers.

In this embodiment, the length of the drawing heads 106a-106c isselected same as the width of the drawing area of the substrate, therebyadditionally providing the following advantages;

(1) The configuration of the apparatus can be made simple, since thestroke of the XY-stage 103 in the X-direction is only required foralignment and the stroke can therefore be made smaller; and

(2) The area occupied by the apparatus can be made smaller because ofthe reduced stroke in the X-direction.

FIG. 14 shows an image of the arrangement of the drawing heads in stillanother embodiment of the color filter producing apparatus of thepresent invention, wherein components equivalent to those in theforegoing embodiment are represented by the same numbers.

In this embodiment, as plural heads (106a1-106an, 106b1-106bn,106c1-106cn) are so arranged that the length thereof is equal to orlarger than the width of the drawing area on the substrate, it caneasily adapt to the change in the substrate size, in addition to theforegoing advantages.

FIG. 15 is a block diagram of a color filter producing apparatusembodying the present invention.

In FIG. 15, there are shown a host computer 201 for controlling theentire apparatus; a control unit 202 for a stage 209; a control unit 203for a coloring ink jet head 208; an image processing unit 204 forprocessing the image signal from a sensor 207; a control unit 205 for acorrecting ink jet head 206; a sensor 207 detecting the ink dischargefrom the ink jet head 208; a posture adjustment control unit 201a forcontrolling the posture of the coloring ink jet head 208 and thecorrecting ink jet head 206, and a stage 209. The ink jet head 208 isused for coloring, while the ink jet head 206 is used for ink dischargefor correcting, in case of an error in the coloring by the head 208. Ahead unit 210 is constituted by the coloring head 208, the sensor 207and the repairing head 206.

FIG. 16 is a view showing schematically the positional relationship ofthe coloring head 208, the repairing head 206, the sensor 207 and thestage 209. A glass substrate 12 to be colored is provided thereon, inadvance, with a dyed layer 14 as explained before. The stage 209 is soconstructed as to be capable of moving the substrate 12 in the X- andY-directions and to rotate the same around the θ-direction. 215indicates the ink discharged in the Z-direction. There are also providedposture adjustment mechanisms 202a, 202b for respectively adjusting theposture of the coloring head 208 and the repairing head 206 in the X, Y,Z and θ directions. In each mechanism, the movement in each direction ismade possible for example by a combination of a linearly movable stageand a rotatable stage. The movement in each direction may be mademanually or by a suitable drive source such as a motor.

The coloring head 208, the sensor 207 and the repairing head 206 arerendered movable, relative to the substrate 12, in the X- andY-directions, by the movement of the either in these directions whilethe other is maintained fixed. Each of the coloring head 208 and therepairing head 206 has linearly arranged plural ink discharge apertures.

FIG. 17 shows the structure of a single-color ink jet head IJHconstituting the coloring head 208 or the repairing head 206 mentionedabove. The head 208 or 206 is provided with such single-color ink jethead IJH for each of red, green and blue colors, so that the coloringhead 208 or the correcting head 206 is constituted by three ink jetheads IJH.

Referring to FIG. 17, the ink jet head IJH is composed of a heater board104, consisting of a substrate bearing plural heaters 102 for inkheating, and a ceiling board 106 for covering the heater board 104. Theceiling board 106 is provided thereon with plural discharge apertures108, behind which there are formed tunnel-shaped liquid paths 110communicating therewith. Each liquid path 110 is separated from theneighboring ones by partitions 112. The liquid paths 110 are commonlyconnected, at the rear, to an ink chamber 114 which receives ink supplyby way of an ink supply aperture 116 and sends the ink to the liquidpaths 110.

The heater board 104 and the ceiling board 106 are mutually assembled insuch a manner that the heaters 102 respectively correspond to the liquidpaths 110, as shown in FIG. 17. Though FIG. 17 illustrates only twoheaters 102, a heater 102 is provided for each of the liquid paths 110.By the supply of a predetermined driving pulse to the heater 102 in theassembled state shown in FIG. 17, the ink on the heater 102 boils togenerate a bubble, and is discharged from the discharge aperture 108 bythe expansion of the bubble. The size of the bubble can be controlled bythe control of the driving pulse, for example the power thereof, appliedto the heater 102, so that the volume of the ink discharged from theaperture can be arbitrarily controlled.

FIGS. 18A and 18B show the positional relationship between the coloringor correcting head and a translucent area (filter element) formed on theglass substrate 12 to be colored, respectively in case the distance ofthe ink discharge apertures for coloring is same as or different fromthe distance of the translucent areas formed on the glass substrate 12.In FIG. 18A, there are shown the coloring head 208, an ink dischargeaperture 217, a filter element (optically translucent area) 10a formedon the substrate 12, and an ink dot 219 that has been discharged fromthe aperture 217 and has reached. In this case, since the pitch L of theink discharge apertures 217 is same as the pitch W1 of the filterelements 10a, the glass substrate 12 and the coloring head 208 have azero rotational relationship as illustrated. On the other hand, if thepitch L of the ink discharge apertures 217 is different from the pitchW2 of the filter elements 10a as shown in FIG. 18B, the coloring head208 can be adjusted to an angle θ represented by:

    W2/L=cosθ

relative to the glass substrate 12, and the coloring operation is madepossible for any pitch of the filter elements 10a on the substrate 12.

In the following there will be explained the coloring method when thecoloring head and the glass substrate are set in a predetermined angularrelationship.

In FIG. 19A, the coloring head 208 and the glass substrate 12 are setwith a mutual angle θ, and it is assumed that they mutually move in adirection 227 with a relative speed S. In this state, the plural inkdischarge apertures for coloring have a pitch H1 in the horizontaldirection, while the filter elements 10a has a pitch H2 in the direction227 of relative movement. FIG. 19B shows the discharge timing of the inkdischarge apertures. The ink discharge is started at timings t1, t2 andt3 respectively for the first, second and third discharge apertures. Therelationship among t1, t2, t3 is determined by the relative speed S andthe horizontal pitch H1 of the discharge apertures by:

    (t2-t1)=H1/S

    (t3-t2)=H1/S.

Also the pitch t of the discharges of a discharge aperture for thefilter elements 10a adjacent in the direction of relative movement isdetermined by:

    t=H2/S.

Thus, there can be produced a color filter with an arbitrary pitch ofthe filter elements 10a, without requiring a coloring head with aparticular pitch of the ink discharge apertures, through the control ofthe ink discharge timing. Although the foregoing description has beenmade on a single coloring head, a similar process is evidentlyrealizable with plural heads.

In the following there will be explained a case of employing pluralcoloring heads. FIGS. 20A and 20B shows a case of employing pluralcoloring heads respectively for red, green and blue colors.

In FIG. 20A, a coloring head 208 is composed of plural ink jet heads IJHfor discharging red, green and blue inks. Ink discharge apertures 217are so positioned as to deposit the R, G, B inks in repeated cycles in adirection perpendicular to the direction 227 of relative movement,thereby forming filter elements 10a of a same color in theabove-mentioned direction 227. The coloring head 208 and the glasssubstrate 12 are mutually set by an angle θ, and it is assumed that theymutually move in a direction 227 by a relative speed S. In this state,the plural ink discharge apertures in the coloring head 208 havehorizontal pitches Wrg, Wgb. A sensor 207, composed of an image pickupdevice such as a line sensor, is positioned behind the plural ink jetheads IJH. FIG. 20B shows the timing of discharges from the inkdischarge apertures. The R coloring head starts ink discharge at timingsRT1, RT2, RT3 respectively for the first, second and third apertures.The G coloring head starts ink discharge at timings GT1, GT2, GT3respectively for the first, second and third apertures.

The B coloring head starts ink discharge at timings BT1, BT2, BT3respectively for the first, second and third apertures. The relationshipamong RT1, GT1 and BT1 is determined, according to the relative speed Sand the horizontal pitches Wrg, Wgb of the ink discharge apertures ofthe R, G, B coloring heads by:

    (GT1-RT1)=Wrg/S

    (BT1-GT1)=Wgb/S.

The discharge timings of an ink discharge aperture for the filterelements formed in the direction of relative movement are same asalready explained in relation to FIG. 19B. Also those of the inkdischarge apertures contained in a same ink jet head are same as alreadyexplained in relation to FIG. 19B. In the foregoing description, theplural ink jet heads are composed of red, green and blue coloring heads,thus such three colors are not limitative. For example, the pluralcoloring heads may be for a same color.

In the following there will be explained an adjusting method foradjusting the pitch of the ink discharge apertures of the pluralcoloring heads same as that of the optically translucent areas.

FIG. 21 shows an example of the test pattern of the coloring materialsfor adjustment:, in case of employing R, G and B ink jet heads. Thereare shown dots 233, 234, 235 formed on the glass substrate 12respectively by the R, G and B ink jet heads, wherein the dots alignedin the vertical direction are those of a same color, formed by the inkdischarge apertures in a same ink jet head. There are also shown a R inkdot pitch; Pr, a G ink dot pitch; Pg, a B ink dot pitch; Pb, a pitch Prgbetween the R and G ink dots, and a pitch Pgb between the G and B inkdots. These pitches are measured, and the ink jet heads are so adjustedthat these pitches become equal to the pitches of the filter elements10a.

FIG. 22 is a block diagram of an image processing unit for measuring thereaching positions of the dots by means of a pattern as shown in FIG.21, and FIG. 23 is a flow chart of the adjusting procedure.

In FIG. 22 there are shown a CPU 236 for controlling the imageprocessing unit, connected with the host CPU; a sensor 207 composed forexample of a line sensor, for capturing the reached dots as image data;an image input unit 237 for effecting A/D conversion and corrections,for example for the unevenness in the sensitivity of the line sensor andin the illumination intensity of an unrepresented illuminating system,on the image data obtained by the sensor 207; a non-discharge detectingunit 238 for detecting whether the ink discharge has been made by theink jet heads; an image memory unit 239 for storing the image data fromthe image input unit 237; a cut-out process unit 240 for individuallyseparating and identifying the formed dots; and a center-of-gravitycalculation unit 241 for calculating the position of the center ofgravity of individually separated dot. The image input unit 237, thenon-discharge detection unit 238, the image memory unit 239, the cutoutprocess unit 240 and the center-of-gravity calculation unit 241 aremutually connected by a system bus 242 and a local bus 243. Thenon-discharge detection unit 238 is connected to a coloring head controlunit 203 and a repairing head control unit 205. The sensor 207 ispositioned immediately after the coloring head 238, as shown in FIG.20A, for reading the reached dots of the test pattern shown in FIG. 21,immediately after the formation thereof, but it may also be provided inanother position. In such case, after the formation of the test patternshown in FIG. 21, the formed pattern can be read by moving the stage 209again with a constant speed.

Now reference is made to a flow chart in FIG. 23, for explaining theprocedure of detecting the reached position and adjusting the ink jethead, based on thus detected position. At first a step S1 forms a testpattern as shown in FIG. 21, and a step S2 reads the test pattern by thesensor 207 positioned immediately behind the coloring head 208. In astep S3, the cutout process unit 240 separately discriminates thereached dots, which are stored in the image memory 239. In a step S4,the center-of-gravity calculation unit 41 calculates the position of thecenter of gravity of each dot, separated in the step S3. A step S5determines Pr of R pitch, Pg of G pitch and Pb of B pitch shown in FIG.21, from the centers of gravity of the dots determined in the step S4.Then a step S6 calculates the pitch Prg between the R and G ink dots andthe pitch Pgb between the G and B ink dots, shown in FIG. 21. Then astep S7 discriminates whether the pitches Pr, Pg, Pb determined in thestep S5 are equal to the pitches of the R, G, B filter elements 10aformed on the glass substrate 12. If not equal, a step S10 adjusts theθ-movement mechanism of the coloring head 208 shown in FIG. 16, and thesteps S1 to S7 are executed again. If equal, a step S8 discriminateswhether the pitch Prg of the R and G ink dots and the pitch Pgb of the Gand B ink dots, determined in the step S6 are respectively equal to theR-G pitch and the G-B pitch of the filter elements 10a, and, if notequal, a step S9 adjusts the Y-movement mechanism of the coloring head208 shown in FIG. 16 and the steps S1 to S7 are executed again. Ifequal, the adjusting procedure is completed, and the coloring operationis thus enabled.

In the following there will be explained a method of controlling thedischarge timing of each ink discharge aperture, in case the plural inkdischarge apertures in a same ink jet head have displacements in thelanding positions thereof.

FIG. 24 illustrates such displacements in the reached dot positions,encountered for example in case the discharge apertures of the ink jethead is not scatteringly formed. There are shown reached dots 247, and aline 248 indicating the approximation of thus formed plural dots. Thearrow in FIG. 24 indicates the direction of coloring operation. If theapproximate line 248 is assumed to indicate the ideal landing position,the first dot in FIG. 24 has reached in the proper position, while thesecond dot has reached in front, in the direction of coloring operation,of the ideal position, and the third dot has reached behind the idealposition. With such ink jet head, there can only be obtained a defectivecolor filter, since the ink cannot be accommodated within thecorresponding filter element 10a constituting the color filter.

FIG. 25A shows the positional relationship between the ink jet head IJHinvolving such displaced discharge apertures and the filter elements10a, and FIG. 25B shows the discharge timings of the ink dischargeapertures corresponding to the case of FIG. 25A.

In FIG. 25A, 227 indicates the direction of relative movement of theglass substrate 12 and the ink jet head IJH in the coloring operation.

In FIG. 25B, t1 indicates the discharge timing of the first dischargeaperture, while t2 and t3 are the original discharge timings of thesecond and third discharge apertures. If the apertures in the ink jethead involve scattering displacements as shown in FIG. 25A, the filterelements 10a cannot be precisely colored with such original timings t1,t2, t3. Consequently the discharge timing of each aperture is displacedearlier or later, according to the reaching position. As the firstaperture in FIG. 25A is on the reference position, the discharge timingt1 need not be altered. As the second aperture is positioned in front ofthe reference position, the timing is delayed by Δt2 from t2, and, asthe third aperture is positioned behind the reference position, thetiming is advanced by Δt3 from t3. The filter elements 10a can beprecisely colored by such control of the discharge timing of each inkdischarge aperture, according to the reaching position thereof.

FIGS. 27A and 27B show examples of a color pattern used in checking thereaching positions of the ink discharge apertures of the coloring head.The pattern may be made either in a vertical column as shown in FIG. 27Aby ink discharge from the apertures used for only coloring, among theplural discharge apertures in the coloring head, or by a certain pitchin the coloring direction, as shown in FIG. 27B, by ink discharge fromall the discharge apertures in the coloring head. In the following therewill be explained, with reference to FIG. 26, a procedure of determiningthe reaching positions from such pattern and determining the timings ofink discharge.

FIG. 26 is a flow chart showing a procedure of detecting the reachingposition and controlling the discharge timing. At first a step S21 formsa test pattern as shown in FIG. 27A or 27B, and a step S22 reads thetest pattern by the sensor 207 positioned immediately behind thecoloring head. In a step S23, the cut out process unit 240 separatelydiscriminates each of the reached dots, which are stored in the imagestoring portion 239. In a step S24, the center-of-gravity calculationunit 241 calculates the position of the center of gravity of each dot,separately discriminated in the step S23. Based on the position of thecenter of gravity of each dot calculated in the step S24, a step S25effects linear approximation either for all the dots in case of thepattern shown in FIG. 27A or for each vertical column in case of thepattern shown in FIG. 27B. After the determination of such approximationline, a step S26 calculates the amount of displacement of the center ofgravity of each dot from the approximation line, and a step S27discriminates whether the amount of displacement of each dot is within apredetermined range. If not, the discharge timing has to be adjusted,and a step S29 calculates the adjustment value for the discharge timing,based on the amount of displacement for each dot. The calculated valueis set in the coloring head control unit 203 through the host CPU 201,then a step S30 corrects the discharge timing of each dischargeaperture, and thereafter operations the steps S21 to S27 are executedagain. If the step S27 identifies that the amount of displacement ofeach dot is within the predetermined range, it is judged the adjustmentof the discharge timing is no longer necessary, so that the adjustingoperation is completed.

The above-explained adjustment of the discharge timing based on the inkreaching position is naturally applicable also to the case of utilizingplural ink jet heads. More specifically, in such case, there can beprepared a pattern as shown in FIG. 27A or 27B for the ink jet head ofeach color and executed the operation as shown in FIG. 26.

As explained in the foregoing, the present embodiment enables productionof a precise color filter even in case where the ink reaching positionsfrom the plural ink discharge apertures involve are scatteringdisplaced. It is thus rendered possible to produce a color filter ofhigher quality, suppressing the fluctuation of the precision generatingby each time of the replacement of the ink jet head and stabilizing theobtained quality.

The present invention is not limited to the foregoing embodiments but issubject to various modifications and alterations, within the scope andspirit of the appended claims.

Among various ink jet recording methods, the present invention bringsabout a particular effect when applied to the recording method explainedin the foregoing, provided means (for example electrothermal converterelements or a laser light) for generating thermal energy for the purposeof ink discharge and indicing a state change in the ink by such thermalenergy, so that such system can achieve higher density and highdefinition in recording.

The principle and representative configuration of such recording methodare disclosed, for example, in the U.S. Pat. Nos. 4,723,129 and4,740,796. This system is applicable to so-called on-demand typerecording or continuous type recording.

Above all, the case of the on-demand type recording is particularlyeffective. Namely, that is why, in the case, by applying at least onedrive signal for giving rising of a rapid temperature over a filmboiling temperature of the liquid corresponding to a recordinginformation to an electrothermal converter disposed corresponding to asheet or a liquid chanel holding a liquid (ink), a thermal energy isgenerated in the electrothermal converter to generate the film boilingat a heat action surface of the recording head, so that a bubble in theliquid (ink) corresponding to the drive signal can be formed, havingrelationship of one bubble to one drive signal. The ink is dischargedthrough the discharge aperture by the growth and contraction of thebubble, thereby forming at least one liquid droplet. The drive signal ispreferably formed by a pulse form, as it realizes instantaneous growthand contraction of the bubble, thereby attaining highly responsivedischarge of the ink.

Such pulse-shaped drive signal is preferably that disclose in the U.S.Pat. Nos. 4,463,359 and 4,345,262. Also the conditions described in theU.S. Pat. No. 4,313,124 relative to the temperature increase rate of theheat action surface allows to obtain further improved recording.

The configuration of the recording head is given by the combinations ofthe liquid discharge apertures, liquid channels and electrothermalconverter elements with linear or rectangular liquid channels, disclosedin the above-mentioned patents, but a configuration disclosed in theU.S. Pat. No. 4,558,333 in which the heat action part is positioned in aflexed area, and a configuration disclosed in the U.S. Pat. No.4,459,600 also are directed to a gist of the present invention.Furthermore the present invention is effective in a structure disclosedin the Japanese Patent Laid-Open Application No. 59-123670, having aslot common to plural electrothermal converter elements as a dischargeaperture therefor, or in a structure disclosed in the Japanese PatentLaid-Open Application No. 59-138461, having an aperture for absorbingthe pressure wave of thermal energy, in correspondence with eachdischarge aperture.

A full-line type recording head having a length corresponding to amaximum width of a recording medium to which data can be recorded by arecording apparatus may be constructed by plural recording heads socombined as to provide the required length as disclosed in theabove-mentioned patents, or may be constructed as a single integratedrecording head, and the present invention can more effectively exhibitits advantages in such recording head.

The present invention is furthermore effective in a recording head ofinterchangeable chip type, which can receive ink supply from the mainapparatus and can be electrically connected therewith upon mounting onthe main apparatus, or a recording head of cartridge type in which anink tank is integrally constructed with the recording head itself.

Also the apparatus is preferably provided with the emission recoverymeans and other auxiliary means for the recording head, since theeffects of the recording head of the present invention can be stabilizedfurther. Examples of such means for the recording head include cappingmeans, cleaning means, pressurizing or suction means, preliminaryheating means composed of electrothermal converter element and/oranother heating device, and means for effecting an idle ink dischargeindependent from the recording operation, all of which are effective forachieving stable drawing operation.

Furthermore, the recording head of the present invention is applicable,not only to liquid ink, but also to the ink which is solid below roomtemperature but softens or liquefies at room temperature, or whichsoftens or liquefies within a temperature control range from 30 to 70°C., which is ordinarily adopted in the ink jet recording. Thus the inkonly needs to be liquidous when the recording signal is applied.

Besides the recording head of the present invention can employ inkliquefied by thermal energy provided corresponding to the recordingsignal, such as the ink in which the temperature increased by thermalenergy is intentionally absorbed by the state change from solid toliquid, or the ink which remains solid in the unused state for thepurpose of prevention of ink evaporation, or the ink which starts tosolidify upon reaching the substrate. In these cases, the ink may beholded as solid or liquid in recesses or holes of a porous sheet, asdescribed in the Japanese Patent Laid-Open Application Nos. 54-56847 and60-71260, and placed in an opposed state to the electrothermal converterelement. The present invention is most effective when theabove-mentioned film boiling is induced in the ink of theabove-mentioned forms.

What is claimed is:
 1. A color filter producing apparatus comprising:aset of drawing heads for respectively generating ink jets of red, greenand blue colors; distance detection means for detecting a distance in aZ-direction between a substrate on which a color filter is to be formedby drawing with said ink jets and said set of drawing heads; reachingposition detecting means for detecting a reaching position on saidsubstrate of each of ink jets discharged from said drawing heads;alignment error detecting means for detecting an error of alignmentbetween said substrate and said drawing head in an XY-plane intersectingsaid Z-direction; and alignment means for effecting alignment betweensaid substrate and said set of drawing heads in said Z-direction basedon said detected distance by said distance detection means and effectingalignment between said substrate and said set of drawing heads in saidXY-plane based on said detected alignment error by said alignment errordetecting means.
 2. An apparatus according to claim 1, wherein saiddrawing heads are fixed above said substrate, and said alignment meansis adapted to move said substrate.
 3. An apparatus according to claim 1,wherein, said drawing heads are aligned to predetermined positions to asurface of said substrate.
 4. An apparatus according to claim 1, whereina length of said drawing heads of red, green and blue colors is equal toa width of said substrate in a drawing direction.
 5. An apparatusaccording to claim 1, wherein plural sets of the drawing heads arearranged in parallel manner, with an entire length thereof being equalto a width of said substrate in a drawing direction.
 6. An apparatusaccording to claim 1, wherein said drawing heads are adapted toindependently generate ink jets of red, green and blue colors, saidalignment means is adapted to maintain a predetermined distance fromsaid drawing heads to said substrate, and said relative displacement andsaid alignment are performed in directions of six degrees of freedom. 7.A color filter producing method comprising steps of:providing a colorfilter producing apparatus, said color filter producing apparatuscomprising a set of drawing heads for respectively generating ink jetsof red, green and blue colors; distance detection means for detecting adistance between a substrate on which a color filter is to be formed bydrawing with said ink jets and said set of drawing heads in aZ-direction; reaching position detecting means for detecting a reachingposition on said substrate of each of ink jets discharged from saiddrawing heads; alignment error detecting means for detecting an error ofalignment between said substrate and said drawing head in an XY-planeintersecting said Z-direction; and alignment means for effectingalignment between said substrate and said at least a set of drawingheads in said Z-direction and effecting alignment between said substrateand said at least a set of drawing heads in said XY-plane based on saiddetected alignment error by said alignment error detecting means andsaid detected reaching position by said reaching position detectingmeans; detecting said reaching position on said substrate of said inkjet discharged from said drawing head; and effecting alignment betweensaid substrate and said drawing head in said XY-plane based on saiddetected alignment error by said alignment error detecting means andsaid detected reaching position by said reaching position detectingmeans.
 8. A method for producing a color filter by discharging acoloring material from an ink jet head to an optically translucentsubstrate thereby forming a plurality of colored filter elements withsaid coloring material, comprising:a first discharge step of dischargingthe coloring material with a predetermined pattern from said ink jethead under a scanning motion thereof relative to said opticallytranslucent substrate for coloring said substrate; a detection step ofdetecting a reaching position of said coloring material in said firstdischarge step; a timing adjustment step of adjusting a timing ofdischarge of said ink jet head based on a result of detection of thereaching position of said coloring material detected in said detectionstep; and a second discharge step of discharging the coloring materialfrom said ink jet head with the timing set in said timing adjustmentstep and scanning said ink jet head relative to said substrate, therebycoloring the filter elements on said substrate.
 9. A method according toclaim 8, wherein said ink jet head discharges the coloring material byutilizing thermal energy, and is provided with a thermal energyconversion member for generating thermal energy to be given to thecoloring material.
 10. A method for producing a color filter bydischarging a coloring material from an ink jet head having pluraldischarge nozzles to an optically translucent substrate thereby forminga plurality of colored filter elements with said coloring materialarranged on said substrate comprising:a first discharge step ofdischarging the coloring material with a predetermined pattern from saidink jet head while scanning said ink jet head relative to said opticallytranslucent substrate for coloring; a detection step of detecting areaching position on said optically translucent substrate of saidcoloring material in said first discharge step; a posture adjustmentstep of adjusting a posture of said ink jet head based on the result ofdetection of the reaching position of said coloring material detected insaid detection step; and a second discharge step of discharging thecoloring material from said ink jet head with the posture set in saidposture adjustment step and scanning said ink jet head relative to saidsubstrate, thereby coloring the filter elements on said substrate.
 11. Amethod according to claim 10, wherein said ink jet head discharges thecoloring material by utilizing thermal energy, and is provided with athermal energy conversion member for generating thermal energy to begiven to the coloring material.
 12. A color filter produced by theprocess of any of claims 7-11.
 13. A liquid crystal display device,comprisingthe color filter according to claim 12; a substrate opposed tosaid color filter; and a liquid crystal compound sealed between saidcolor filter and said substrate.
 14. A liquid crystal apparatus,comprising:the liquid crystal display device according to claim 13; andimage signal output means for outputting an image signal to said liquidcrystal display device.
 15. An apparatus for producing a color filter byforming a plurality of colored filter elements arranged on an opticallytranslucent substrate comprising:an ink jet head having a plurality ofdischarging nozzles for discharging a coloring material, moving relativeto said substrate to color said filter elements; detecting means fordetecting a liquid droplet of said coloring material so as to detect areaching position of said coloring material discharged by said ink jethead; and adjustment means for adjusting the posture of said ink jethead and a positional relationship among said plurality of dischargingnozzles based on the result of detection of the reaching position ofsaid coloring material detected by said detecting means.
 16. Anapparatus for producing a color filter by forming a plurality of coloredfilter elements arranged on an optically translucent substratecomprising:an ink jet head for discharging a coloring material, movingrelative to said substrate to color said filter elements; detectionmeans for detecting a liquid droplet of said coloring material so as todetect a reaching position of said coloring material discharged by saidink jet head; and adjustment means for adjusting the timing of dischargeof said ink jet head based on the result of detection of the reachingposition of said coloring material detected by said detection means,wherein said ink jet head is adapted to discharge the coloring materialby utilizing thermal energy and provided with a thermal energyconversion member for generating thermal energy to be given to thecoloring material.
 17. An apparatus for producing a color filter byforming a plurality of colored filter elements arranged on an opticallytranslucent substrate, comprising:an ink jet head provided with pluraldischarge nozzles for discharging a coloring material onto saidsubstrate, moving relative to said substrate to color said filterelements; detection means for detecting a liquid droplet of saidcoloring material so as to detect a reaching position of said coloringmaterial discharged by said ink jet head; and adjustment means foradjusting a position of one of said plurality of discharging nozzles ofsaid ink jet head relative to a position of the other one thereof basedon the result of detection of the reaching position of said coloringmaterial detected by said detection means.
 18. An apparatus according toclaim 17, wherein said ink jet head is adapted to discharge the coloringmaterial by utilizing thermal energy and is provided with a thermalenergy conversion member for generating thermal energy to be given tothe coloring material.
 19. An apparatus for producing a color filter byforming a plurality of colored filter elements arranged on an opticallytranslucent substrate comprising:an ink jet head provided with pluraldischarge nozzles for discharging a coloring material moving relative tosaid substrate to color said filter elements; and adjustment means forthree-dimensionally adjusting the posture of said ink jet head and apositional relationship among said plural discharge nozzles of said inkjet head.
 20. An apparatus according to claim 19 further comprisingdetection means for detecting a reaching position of the coloringmaterial discharged by said ink jet head.